Which planet is most similar to Earth?

Among all planets in the solar system, Venus is considered the most similar to Earth in terms of size, mass, and composition.

At first glance, Venus and Earth are often called “twin planets” because:

• Their diameters are almost the same
• Both are rocky (terrestrial) planets
• They have similar internal structures (core, mantle, crust)

However, the similarity is mostly physical, not environmental.

Key differences:

• Venus has an extremely thick carbon dioxide atmosphere
• Surface temperatures reach around 465°C, making it the hottest planet
• Atmospheric pressure is about 90 times higher than Earth’s
• No liquid water exists on its surface

In contrast, Earth has a balanced atmosphere, moderate temperature, and abundant water, making it suitable for life.

Important distinction: While Venus is structurally similar to Earth, Mars is often studied for habitability comparisons, as it shows signs of past water and more Earth-like surface conditions.